Try squares come in a range of sizes, with blades from 2″ to 24″ and longer. While some are made entirely out of wood, most are either all metal or a metal/wood combination. The blade is a crucial part of the square. Avoid squares with thin, flexible blades, those that have rounded over edges, and those with hard to read scales, and select one that feels comfortable in your hands.

It’s convenient to have at least three try squares in your shop: one with a long blade for general layout and carcass work; a 6″ to 8″ precision square where accuracy is critical; and a 2″ to 4″ square for detailed work. As with most hand tools, you get what you pay for. A good quality square will not be inexpensive, but will last a lifetime if properly cared for.

After purchasing a square check it for accuracy. Align the handle along a straight edge and draw a line down along the blade. Flip the handle over along the edge, and draw another line in the same place. If the lines are parallel, keep the square, it’s accurate; if the lines converge or diverge, the square isn’t accurate, return it for another square or a refund. Treat your square with care: don’t use it to pry the lid off a paint can; never use the handle as a hammer; and don’t toss it carelessly onto your work bench.

When using a square it’s important to hold the handle tightly against the stock with the blade pressed firmly on the stock. This ensures the square doesn’t move about when using it. To mark a line use either a sharp pencil, or better yet, a marking knife, which scores the grain with a clean, crisp line. When using the square to test an inside or outside corner, or checking if the blade on your table saw or the fence on your jointer is set at 90º, hold the square firmly and sight along the blade and arm. Good lighting will make the job easier.

The Nobex comes in a range of sizes. It’s unique in that the blade pivots to three common angles: 90º, 45º and 135º, and folds flush into the arm. While not as precise as the other squares we looked at, it works well for general layout, and is particularly handy if you do much cabinetry. The scale is a bit hard to read in dim lighting, and it can’t be re-calibrated if it gets out of square.

The Crown is a staple style, similar to the ones sold by Marples, Sorby, Freud and others. It has a hardened, tempered and blued steel blade with a Rosewood handle and comes in a range of sizes. The one we tested was out of square and it can’t be recalibrated. We liked the wide blade, but it lacks a scale. Reasonably priced, it makes a none too bad general layout tool where precision isn’t an issue. Lee Valley carries a couple of the smaller Crown squares, contact Crown Tools directly for other models.

This is one suave square; at $129 US it’s the Porsche of squares. Beautiful to look at and a real pleasure to use. Surprisingly, this one was slightly out of square when it arrived, although it was easy to recalibrate with a simple hex key. The blade is made of satin chromed, hardened steel, and the scale (available either metric or imperial) is precisely aligned with both faces of the handle. The edges of the blade are square, but not sharp and the scale is easy to read, even in dim light. The handle is made of Jaura (a composite of wood and resin). One nice feature is the built-in slide stop; a handy lever that slides out and locks in place, aligning the square to your stock. The square is a tad unbalanced due to the weight of the handle. If you’re looking for the ultimate in accuracy in a scaled blade, check out the AS-9.

If the Bridge City AS-9 is a Porsche, then think of the Incra as a Corvette. Available in both a 5″ and 7″ version it was dead accurate. It’s made by a unique manufacturing process, which cuts the body of the square out of a solid slab of hardened aluminum. The red side arms are then fixed to the body. It lacks a scale, but due to precise machining, you can use the body itself for some common measurements: the base is exactly 3/4″ wide and the blade 1/4″ thick and 1 1/2″ wide. The edges of the square are crisp, but not sharp. A great feature is the support lip that holds the square on the edge of stock. A tapped screw hole in the blade allows you to add a fence to the blade. If you can live without a scaled blade, than this ultimately precise square is worth looking at.

Lee Valley sells these steel bodied squares in a range of sizes. This 4 inch model was marginally out of square (under .010). There is no scale on the blade, and they can’t be recalibrated. For the price you can afford to have several left conveniently around the shop. These squares fit conveniently into an apron pocket. While they are rather bland tools, they do get the job done.

We were excited about testing the Starrett 13, which is also called a double square. The handle moves along the blade; you can use it to mark out on either side of the handle. It makes a good depth gauge, especially useful when setting the height of router bits or saw blades. There is also a handy spirit level in the handle. The heft and feel of this square is great, the scale is easy to read, and the edges of the blade and handle are crisp. This is a great multi-function square that belongs in every woodworking shop. Unfortunately the model we tested was significantly out of square; one edge of the blade was concave, deflecting about .016″. Several other woodworkers who own this square report that theirs is dead on accurate. So this shouldn’t deter you from considering this square; it’s guaranteed and a return to the dealer nets a replacement.

Lee Valley, 800-267-8767, www.leevalley.com;
Crown Hand Tools, www.crownhandtools.ltd.uk;
Woodcraft Supply, 800-225-1153, www.woodcraft.com;
Bridge City, 800-253-3332, www.bridgecitytools.com;
Acklands Grainger, www.acklandsgrainger.com